Trailer with adjustable ground clearance

Abstract

A simple mechanical height adjustment device adjusts the ground clearance of a trailer. The trailer, having the height adjustment device can selectably and reversibly increase its ground clearance. The trailer, having an adjustable ground clearance, can minimize its load height when operating on improved roads in order to meet local and state height regulation, but can increase its ground clearance on uneven roads.

1. A vehicle trailer comprising:
 (a) a rear deck; 
 (b) a forward deck having a second end; 
 (c) a central deck having a front end and a rear end, wherein the rear end is attached to the rear deck to form a rigid unitary structure; and 
 (d) a pair of pivotable altitude adjustment mechanisms connecting the front end of the central deck to the second end of the forward deck, wherein each altitude adjustment mechanism includes
 a first rear pivot plate having a pivot hole and a first position locking pin hole and a second position locking pin hole. the first rear pivot plate mounted on a corner of the front end of the central deck parallel to and offset a longitudinal midplane of the trailer, 
 a second rear pivot plate having a pivot hole and a first position locking pin hole and a second position locking pin hole. the second rear pivot plate mounted on the front end of the central deck parallel to the first rear pivot plate and offset from the first rear pivot plate towards the longitudinal midplane of the trailer. 
 a forward pivot plate having a pivot hole and a first position locking pin hole and a second position locking pin hole. the forward pivot plate mounted on the second end of the forward deck and positioned between the first and second rear pivot plates to coaxially align the pivot hole of the forward pivot plate with the pivot holes of the first and second rear pivot plates, and 
 a pivot pin connecting the coaxially aligned pivot holes of the forward pivot plate and the first and second rear pivot plates; 
 
 (e) an adjustment means for moving the front end of the central deck to an up position or a down position, wherein the up position coaxially aliens the first locking pins holes of the forward pivot plate and the first and second rear pivot plates and the down position coaxially aligns the second locking pins holes of the forward pivot plate and the first and second rear pivot plates; and 
 (f) a selectable engageable position locking pin connecting coaxially aligned locking pin holes to lock the front end of the central deck in either the up position or the down position. 
 
     
     
       2. The vehicle trailer of  claim 1 , wherein the adjustment means include a pair of jacks vertically mounted to the altitude adjustment mechanism on the front end of the central deck. 
     
     
       3. The vehicle trailer of  claim 2 , wherein the jacks have a first end that is reciprocably extendable to move front end of the central deck to the up position or the down position. 
     
     
       4. A vehicle trailer comprising:
 (a) a rear deck; 
 (b) a forward deck having a first end and a second end; 
 (c) a central deck having a front end and a rear end, wherein the rear end is attached to the rear deck; and 
 (d) a pair of pivotable altitude adjustment mechanisms connecting the front end of the central deck to the second end of the forward deck, wherein each altitude adjustment mechanism includes
 (i) a pair of rear pivot plates mounted on the front end of the central deck parallel to and offset from a longitudinal midplane of the trailer, wherein each rear pivot plate has a pivot hole and a first and a second position locking pin holes, 
 (ii) a forward pivot plate mounted on the second end of the forward deck parallel to and offset from the longitudinal midplane of the trailer, wherein the forward pivot plate has a pivot hole and a first and second position locking pin hole, and 
 (iii) a pivot pin connecting the pivot hole of the forward pivot plate to the pivot holes of the pair of rear pivot plates when the pivot holes of the forward pivot plate and the rear pivot plates are coaxially aligned; and 
 
 (e) a jack fixedly mounted to each altitude adjustment mechanism perpendicular to the longitudinal midplane of the trailer, wherein each jack is selectably extendable for moving the front end of the central deck to an up position or a down position, wherein the up position coaxially aligns the first locking pins holes of the forward pivot plate and the first and second rear pivot plates and the down position coaxially aligns the second locking pins holes of the forward pivot plate and the first and second rear pivot plates; and 
 (f) a selectably engageable position locking pin connecting coaxially aligned locking pin holes to lock the front end of the central deck in either the up position or the down position. 
 
     
     
       5. The vehicle trailer of  claim 4 , wherein the altitude adjustment mechanism has a single pivot point. 
     
     
       6. The vehicle trailer of  claim 5 , wherein the pivot point has an axis transverse to the longitudinal midplane of the vehicle trailer. 
     
     
       7. The vehicle trailer of  claim 4 , wherein the position locking pin is secured within the coaxially aligned position locking pin holes with a position locking keeper pin. 
     
     
       8. The vehicle trailer of  claim 4 , wherein the two altitude adjustment mechanisms are symmetrically mounted about the longitudinal midplane of the trailer. 
     
     
       9. A vehicle trailer comprising:
 (a) a rear deck; 
 (b) a forward deck having a first end and a second end; 
 (c) a central deck having a front end and a rear end, wherein the rear end is attached to the rear deck to form a rigid unitary structure; and 
 (d) a pair of pivotable altitude adjustment mechanisms connecting the front end of the central deck to the second end of the forward deck, wherein each altitude adjustment mechanism includes
 (i) a first rear pivot plate having a first pivot hole and a first position locking pin hole located vertically at a radius R from the first pivot hole and a set distance from an arcuate edge of the first rear pivot plate and a second position locking pin hole located at an angle ΦA from the first position locking pin at about the radius R from first pivot hole and substantially the same distance from the arcuate edge of the first rear pivot plate as the first position locking pin hole, wherein a vertical edge of the first rear pivot plate is mounted on the front end of the central deck parallel to and offset from the longitudinal midplane of the trailer, 
 (ii) a second rear pivot plate having a second pivot hole and a first position locking pin hole and a second position locking pin hole, wherein the second rear pivot plate is mounted on the front end of the central deck parallel to the first rear pivot plate and offset from the first rear pivot plate towards the longitudinal midplane of the trailer and wherein the first and second pivot holes are coaxially aligned and the first and second locking pin holes of the first and second rear pivot plates are coaxially aligned, 
 (iii) a forward pivot plate mounted on the second end of the forward deck parallel to and offset from the longitudinal midplane of the trailer, wherein the forward pivot plate has a pivot hole and a first position locking pin hole and a second position locking pin hole, and 
 (iv) a pivot pin connecting the pivot hole of the forward pivot plate to the pivot holes of the pair of rear pivot plates when the forward pivot plate is positioned between the first and second rear pivot plates and the pivot holes of the rear pivot plates are coaxially aligned with the pivot hole of the forward pivot plate, and 
 (v) a selectably engageable position locking pin connecting one of two coaxially aligned position locking pin hole sets, wherein a first set of position locking pin holes includes the first position locking pin hole of the forward pivot plate and the first position locking pin hole in each rear pivot plate and a second set of position locking pin holes includes the second position locking pin hole of the forward pivot plate and the second position locking pin hole in each rear pivot plate, and 
 
 (e) a jack fixedly mounted to each altitude adjustment mechanism on the front end of the central deck. wherein a first end of each jack is selectably extendable to bear perpendicularly against a roadway to move the front end of the central deck to coaxially align the first set of position locking pin holes or the second set of position locking pin holes; 
 whereby each set of position locking pin holes is associated with a particular ground clearance for the front end of the central deck.